The present invention concerns a device for cooling a gas to below its dew point by heat exchange with a low boiling liquefied gas.
Non-dried gases can be cooled only to above their dew points, because if the temperature drops to below the dew point, the moisture separates in the form of ice and clogs the pipes. This applies especially to the cooling of air, which is needed as a cooling agent for many industrial processes, e.g. in the manufacture of plastic film tubing, or for cooling profile bands. If ice formation is to be avoided, the air must be pre-dried, which is very expensive.
Thus, for example, a device for cooling endless profiles, which is known from the German Gebrauchsmuster No. 77 31 245, and which consists basically of a double-walled cooling pipe, in whose annular space a low-boiling liquefied gas evaporates and flows into the inside of the pipe, can also be used to cool a warm gas, but only to the dew point. If the temperature decreases to below the dew point, the pipe cross section in the zone of the inflow opening for the low-boiling liquefied gas becomes plugged with ice.